﻿/* ==============================================================================
*
*   Copyright (c) 2010, Pierre Favier
*   All rights reserved.
*
*   NTasking is free software: you can redistribute it and/or modify it
*   under the terms of the GNU General Public License as published by the
*   Free Software Foundation.
*
*   Redistribution and use in source and binary forms, with or without
*   modification, are permitted provided that the following conditions
*   are met:
*
*   -   Redistributions of source code must retain the above copyright notice,
*       this list of conditions and the following disclaimer.
*
*   -   Redistributions in binary form must reproduce the above
*       copyright notice, this list of conditions and the following
*       disclaimer in the documentation and/or other materials
*       provided with the distribution.
*
*   THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
*   WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
*   OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
*   DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
*   BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
*   EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
*   TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
*   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
*   ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
*   TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
*   THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
*   SUCH DAMAGE.
*
* ============================================================================== */

using System;

namespace NTasking.Internals
{

    /// <summary>
    /// Define the base properties and methods common to <see cref="CallContext"/> and <see cref="ExecutionContext"/>
    /// </summary>
    internal abstract class ContextBase
    {

        private Exception _exception;


        /// <summary>
        /// Gets or sets a value indicating whether this instance's result has been set.
        /// </summary>
        /// <value><c>true</c> if this instance result is set; otherwise, <c>false</c>.</value>
        internal bool ResultIsSet { get; private set; }


        /// <summary>
        /// Gets or sets the exception thrown by execution of this instance
        /// </summary>
        /// <value>The exception thrown by execution of this instance or <c>null</c> if no exception was thrown.</value>
        internal Exception Exception
        {
            get
            {
                return _exception;
            }

            set
            {
                _exception = value;
                ResultIsSet = true;
            }
        }


        /// <summary>
        /// Mark this instance as having been executed
        /// </summary>
        internal void SetResult()
        {
            ResultIsSet = true;
        }


        /// <summary>
        /// Checks if execution of this instance has thrown an exception; if yes, re-throws the exception.
        /// </summary>
        internal void CheckResult()
        {
            if (!ResultIsSet)
                throw Errors.ResultNotSet();

            if (Exception != null)
                throw Exception;
        }

    }

}